A cableway installation allows passengers, usually skiers, to travel up slopes. At the current time several types exist. Particular mention is made of installations of drag lift, chair lift, gondola and cable-car type.
A cableway installation conventionally comprises an embarking point for passengers and a disembarking point connected by a travel cable supported by towers and having the form of a closed loop. Vehicles such as seats or cabins are suspended via a grip on a carrier or travel cable; the cable is supported by towers and is driven by means of pulleys to cause the vehicles to travel forward.
Cableway installations have to transport a large number of passengers at a high safety level.
If the cableway installation is of chairlift type, the vehicles are chairs which may or may not be detachable.
In the first case, each chair can be disengaged i.e. can be separated from the main travel cable when it comes alongside the embarking or disembarking point. The chair is then led onto a sidetrack on which the travel speed of the chair is more limited. The boarding or disembarking of passengers is therefore able to take place with greater safety, the comfort of use for passengers additionally being improved.
In the second case, if the chairs are not detachable, they remain on the cable even at the boarding and disembarking points. The complexity of this type of installation is therefore reduced since no detaching system is required.
In all cases, the chairs travel above the ground, generally at quite a height above the ground.
It must therefore be ensured that each passenger, and in particular children, cannot accidentally fall over or under the safety rail.
For this purpose it is known to use a retaining system such as the one described in document WO 2007/135256.
A retaining system of this type comprises a magnetic member arranged on each chair, cooperating with a magnetisable element worn by a passenger being transported on the chair, so as to retain the passenger when the chair is travelling outside a disembarking point and to release said passenger when the chair passes through the disembarking point.
The retaining system also comprises first electric coupling means electrically connected to the magnetic member and arranged on the chair, and second electric coupling means receiving an electric current and arranged at the disembarking point so as to cooperate with the first electric coupling means when the chair passes through said disembarking point.
The magnetic member is arranged to retain the passenger when it is not supplied with electric current, and to release the passenger when it receives an electric current.
In this way, it is ensured that the passenger equipped with the magnetisable element is retained on the chair. Risks of falling are therefore limited.
The second electric coupling means arranged at the disembarking point are formed of contact brushes.
The contact brushes conventionally used require proper positioning of the first electric coupling means, and hence of the chair, at the disembarking point. Said positioning can be obtained if the chairs are detachable. In this case, the swinging movements of the chairs are limited at the boarding and disembarking points where the chairs are detached.
On the other hand, this type of contact brush is more difficult to use in a cableway installation in which the chairlifts are not detachable. In this case, the swinging movements are relatively extensive and it is difficult to establish proper contact between the contact brushes and the first electric contact means. In addition, there is a possibility of deteriorating said contact means and the contact brushes.
Additionally, it may prove to be useful to deliver signals to the passengers, for example safety-related signals.